We hung a rotating nerf missile launcher upside down from the ceiling that shoots folks who push broken tests to our staged for deploy branch (we use TeamCity). It's a work in progress and not a perfect system (we pair a lot so there's no guarantee someone is at their desk), but it's fun and gets people's attention.

Basically this, but automagical: http://www.geeky-gadgets.com/ilaunch-thunder-iphone-controll....